There are a variety of head gaskets known in the prior art. Head gaskets generally comprise relatively thin, generally flat bodies which define a plurality of apertures, including oil and water bores and combustion openings.
In high-compression diesel engines operating at high temperatures and high pressures, it has been a practice for a number of years now to provide head gaskets with armoring adjacent the cylinder or combustion openings to seal the combustion openings and to protect the remainder of the gasket from the effects of the high temperature and pressure. Early armoring covered the entire gasket surface as well as the edges of the combustion openings, and such armoring is typified by the showing in U.S. Pat. No. 1,819,694.
It was found subsequently that armor at or embracing the edges of the gasket body adjacent the combustion openings was sufficient to protect the gasket body and to seal the head and block around the combustion opening. It has also been suggested that head gasket armor be positioned in a combustion opening and be suspended from integral tabs which project from the armor into engagement with the gasket body, and a head gasket of this type is illustrated in U.S. Pat. No. 3,565,449.